DUI (driving under the influence), DWI (driving while intoxicated), and OWI (operating while intoxicated) are similar criminal offenses that involve the operation of a motor vehicle, electric vehicle, or sometimes an otherwise-powered vehicle—including boats, aircraft, and bicycles—by an operator who is under the influence of or intoxicated by alcohol or drugs. Per se (pronounced purr-say) intoxication is intoxication by definition—as defined in the state’s statutes by blood alcohol concentration (BAC) of .08 or more (.05 in Utah). And even if a person is not per se intoxicated, they may be intoxicated by not having the normal use of their mental or physical faculties (abilities), for example, and may be charged with a criminal offense.

In some contexts the terms DUI and DWI are used interchangeably, with some states using one term and other states using the other term to define what is essentially the same criminal offense. But in some states both criminal charges are available and there is a legal distinction between them.

For example, in some states with both criminal offenses, DUI is the criminal offense of operating a vehicle under the influence of prescription or recreational drugs, and DWI is the offense of operating a vehicle while intoxicated by alcohol. In some states DWI refers to per se intoxication when the driver’s BAC is above the threshold defined by statute—.08 (.05 in Utah)—and DUI is a criminal offense charged when the police officer believes the driver is under the influence of alcohol, despite the driver’s BAC being below the statutory threshold of .08. And in some states DUI is a separate offense for drivers under the legal age of drinking (21) who have some alcohol in their system, but less than a .08 BAC.

These and other similar alcohol-related operating offenses—including aggravated or enhanced forms of these offenses—vary from state to state in their definitions and potential punishments and are generally located in a state’s statutes—often in the penal code or criminal code.

In Ohio, DUI (driving under the influence) and OVI (operating a vehicle under the influence) are terms used to describe the same criminal offense, which involves operating a vehicle while impaired by alcohol or drugs. Ohio law uses the term OVI rather than DUI or DWI, which is more commonly used in other states. The state's legal limit for blood alcohol concentration (BAC) is .08, in line with the majority of the United States. If a driver is found to have a BAC of .08 or higher, they are considered to be per se intoxicated. However, a driver can also be charged with an OVI if they are found to be impaired at a lower BAC level, based on other evidence of impairment. For drivers under the age of 21, Ohio enforces a 'zero tolerance' law, with a lower BAC limit of .02. The penalties for OVI in Ohio can include fines, license suspension, and even jail time, depending on the circumstances and whether it is a first or repeat offense. Enhanced or aggravated charges may apply in cases involving higher BAC levels or other aggravating factors.